Adjustable hand splint

ABSTRACT

A multi-function hand splint for immobilizing a hand, wrist, and distal forearm of a user includes a sleeve made of a semi-rigid material. The sleeve includes an elongate shell having a dorsal shell portion and a volar shell portion. Extending adjustably from the dorsal shell portion is a dorsal hood having a metacarpal hood portion and a phalanx hood portion. The metacarpal hood portion forms a dorsiflexion angle of between 60° to 80° with the axis of the forearm so that a comfortable maximal dorsiflexion of the wrist is achieved. The metacarpal hood portion also forms a hood angle of between 75° to 90° with the phalanx hood portion. A palm arch supports extends adjustably from the volar shell portion in order to maintain the hand in the dorsal hood with the wrist in dorsiflexion and the metacarpal-phalangeal joints at an angle greater than about 90° to 105°. A thumb opening is provided between the dorsal hood and palm arch support so that the thumb of the user extends therethrough and all joints of the thumb are free to move. Suitable straps are preferably used to hold the sleeve in radial abutment with the hand, wrist, and distal forearm of the user.

This application is a continuation-in-part of copending application Ser. No. 06/934,856, now U.S. Pat. No. 4,765,319.

FIELD OF THE INVENTION

The present invention relates generally to devices for immobilizing a hand and wrist of a user, and more particularly to an adjustable, universal hand splint which allows use of the fingers and thumb while the hand and wrist are immobilized.

BACKGROUND OF THE INVENTION

Various universal hand splints have been used in the art to stabilize a wrist of a user in a neutral or slight dorsiflexion. Such hand splints are easily applied and removed. However, one of the major problems with hand and wrist injuries is a development of metacarpal-phalangeal joint extension deformities. These various prior art hand splints have not satisfactorily eliminated this problem.

A unitary device for immobilizing the thumb, hand and wrist of a user is disclosed in (Shen) U.S. Pat. No. 4,382,439. The disclosed device includes a shell formed of an integral piece of semi-rigid material having portions shaped to receive the upper forearm, hand, and thumb. This shell is substantially C-shaped with a longitudinal opening along the upper or dorsal side of the device. The wrist dorsiflexion angle is disclosed as being between 10° and 40°, and preferably 30°. A thumb opening is provided on the side of the device through which the top of the thumb extends while the fingers extend almost fully out of the device.

The use of opposed dorsal and palm arch splints to immobilize a forearm, wrist, and hand therebetween has been disclosed in prior art. For example, in (Kearns) U.S. Pat. No. 568,951, the opposed splints are designed to achieve a wrist dorsiflexion angle of 80° to 75° and a radial deviation angle of approximately 18°. A similar device is disclosed in (Kearn) U.S. Pat. No. 315,512 in which the dorsiflexion angle is much smaller. It should be noted that the splints in the both of these patents result in the immobilization of the fingers of the user, although the thumb is evidently not immobilized.

In (Hansard) U.S. Pat. No. 1,469,315, a wrist support device including opposed splints is disclosed in which the splints terminate before the metacarpal-phalangeal joints. This allows full movement of the fingers of the user and additionally allows a sidewards movement of the wrist so that the device can be used as a wrist support for such sports as golf or billiards in which a back and forth movement of the wrist is a defective action.

In (Barbara) U.S. Pat. No. 3,938,509, there is disclosed a lightweight, manually formable splint constructed of an underlying framework of aluminum wire connecting a palm piece, a central holding piece, and a proximal holding piece. The palm support includes a thumb rest and the device is held on the arm of the user by velco straps. The central holding piece is adjustable along the wires and can be anchored in place by means of a tightening screw.

SUMMARY OF THE INVENTION

In accordance with the present invention, an adjustable hand splint for immobilizing the hand, wrist, and distal forearm of a user is provided. The hand splint includes a sleeve in which the hand, wrist, and distal forearm of the user are received. This sleeve is made of a semi-rigid material. The sleeve includes an elongate shell extending over the wrist and distal forearm, and this shell includes a volar shell portion and a separate dorsal shell portion which is partially received in the volar shell portion. Extending adjustably from the dorsal shell portion is a dorsal hood including a metacarpal hood portion which covers the dorsum of the hand and a phalanx hood portion which covers the proximal phalanges. The phalanx hood portion terminates at the proximal phalanges. The metacarpal hood portion forms a dorsiflexion angle of between 60° to 80° with the axis of the forearm so that a comfortable maximal dorsiflexion of the wrist is initially achieved. The metacarpal hood portion forms a hood angle of between 75° to 90° with the phalanx hood portion. A palm arch support extends adjustably from the volar shell portion. This palm arch support extends adjacent the metacarpal hood portion in order to maintain the hand in the dorsal hood with the wrist in dorsiflexion by abutment with the metacarpal hood portion and the metacarpal-phalangeal joints at an angle of greater than about 90° to 105° by abutment of the proximal phalanges with the phalanx hood portion. A thumb opening is also provided between the dorsal hood and palm arch support so that the thumb of the user extends therethrough and all joints of the thumb are free to move. During use, a holding means holds the sleeve in radial abutment with the hand, wrist and distal forearm of the user.

In a preferred embodiment of the hand splint of the present invention, the hood angle is slightly less than 90° and the dorsiflexion angle is about 75°. In addition, the line formed by the apexes of the hood angle forms an angle of about 60° with respect to the longitudinal axis of the hand projected on the metacarpal hood portion. Further, the line formed by the apexes of the hood angle when projected onto the M-L plane forms an angle of about 80° with the forearm axis.

In the preferred embodiment, the holding means includes at least two straps and associated securing means for securing the straps in tension between the volar shell portion and dorsal shell portion in order to radially compress the distal forearm portion. This holding means further includes a strap and associated securing means for securing this latter strap in tension between the volar shell portion and the dorsal hood to maintain the hand in the dorsal hood. Preferably, at least the dorsal shell portion is covered on an inside portion thereof with a resilient material and a plurality of apertures are provided through the dorsal shell portion and resilient material.

It is an advantage of the present invention that the development of metacarpal-phalangeal joint extension deformities is avoided by the placing of the metacarpal-phalangeal joints into flexion.

It is also an advantage of the present invention that even though the hand, wrist, and distal forearm of the user are prevented from movement, the user still retains full thumb motion and full PIP flexion and extension.

It is a further advantage of the present invention that the dorsal hood aids in the correction of dorsal edema of the hand and fingers which is a usual accompaniment of most hand and wrist injuries.

Another advantage of the present invention is that the hand splint maintains gentle contact over the dorsum of the hand and thus positions the hand in the dorsal hood. Therefore, the hand splint of the present invention is additionally usable to treat metacarpal fractures and certain fractures of the proximal phalanx.

Still another advantage of the present invention is that the tightening of the sleeve with the straps to provide some soft tissue compression allows adjustment for the size of the forearm to accommodate for changes in the forearm circumference due to subsistence of edema and muscle atrophy with time.

Other features and advantages of the present invention are stated in or apparent from a detailed description of a presently preferred embodiment of the invention found hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a dorsal (posterior) view of the hand splint of the present invention.

FIG. 2 is a little finger (medial) side view of the hand splint depicted in FIG. 1.

FIG. 3 is a partial view toward the back of the hand viewed along the line 3--3 in FIG. 2.

FIG. 4 is a partial thumb side (lateral) view of the hand splint depicted in FIG. 1.

FIG. 5 is a partial anterior (volar) view of the hand splint depicted in FIG. 1.

FIG. 6 is a schematic perspective view of the hand splint depicted in FIG. 1 with the various planes of an arm interposed thereon.

FIG. 7 is a little finger (medial) side view of an adjustable hand splint embodiment of the present invention.

FIG. 8 is a dorsal (posterior) view of the dorsal hood and dorsal shell portion of the adjustable hand split depicted in FIG. 7.

FIG. 9 is a volar (anterior) view of the palm arch support and volar shell portion of the adjustable hand splint depicted in FIG. 7.

FIG. 10 is a planar view in partial cross section of a rivet used in the adjustable hand splint depicted in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference now to the drawings in which like numerals represent like elements throughout the several views, a hand splint 10 according to a first embodiment of the present invention is depicted in FIGS. 1-6. It should be appreciated that the anatomic position of the forearm which is the basis for the nonmenclature describing the principle planes of the forearm is based upon a person standing in an upright position with the hands and arms extended and hanging downwards with the palms of the hands facing forward. Thus, the posterior or dorsum of the hand is the back of the hand, while the anterior or volar of the hand is the palm of the hand. In this position, the lateral side of the hand (away from the center of the body) is the thumb side whereas the medial side of the hand (closer to the body) is the small finger side. It should also be appreciated that hand splint 10 is depicted as a hand splint for the right hand of a user; and that a hand splint for a left hand would simply be a mirror image of hand splint 10.

Hand splint 10 includes a one-piece sleeve 12 in which the hand, wrist, and distal forearm of the user are received. Sleeve 12 is made of an outer material 14 of molded polyethylene which is lined with an inner material 16 of polyethylene foam. Perforations 18 are provided in outer material 14 and inner material 16 to allow air circulation to the skin of the user.

Sleeve 12 includes an elongate shell 20 which extends over the wrist and distal forearm of the user. Shell 20 is substantially C-shaped in lateral cross section. Longitudinal opening 22 of the C-shape of shell 20 is located in the M-L plane of the forearm, and preferably along the little finger side of hand splint 10 as depicted.

Shell 20 includes a dorsal shell portion 24 and a volar shell portion 26. Attached to dorsal shell portion 24 by use of rivets 28 are two velcro straps 30. Velcro straps 30 include a fibrous portion 32 which are suitably attached to respective hook portions 34. Located on volar shell portion 26 longitudinally opposite velcro straps 30 are rings 36 which are similarly attached by rivet. It should be appreciated that velcro straps 30 are fed through rings 36 and back upon themselves in order for fibrous portions 32 to attach to hook portion 34 and to hold volar shell portion 26 and dorsal shell portion 24 together.

Sleeve 12 also includes a dorsal hood 38 which extends from dorsal shell portion 24. Dorsal hood 38 is formed by a metacarpal hood portion 40 and a phalanx hood portion 42. Metacarpal hood portion 40 forms a dorsiflexion angle A with the forearm axis 44 of between 60° to 80°. Dorsal hood 38 also includes a hood angle of between 75° to 90° formed by metacarpal hood portion 40 and phalanx hood portion 42. In the preferred embodiment of hand splint 10, dorsiflexion angle A is preferably about 75° (±/=5°) and hood angle B is preferably slightly less than 90°.

In order to properly position the hand of a user underneath dorsal hood 38, dorsal hood 38 is configured so that a line 46 representing the apexes of hood angle B is inclined both proximally and anteriorly as shown in FIG. 6. It should be appreciated that line 46 is parallel to the metacarpal-phalangeal joints of the user. When dorsal hood 38 is viewed perpendicular to metacarpal hood portion 40 as depicted in FIG. 3, the angle C between line 46 and line 48 which represents the axis of the hand in the plane of metacarpal hood portion 40 is approximately 60°. It should also be appreciated that this angle is not the same as the projected angle of line 46 in the cross-sectional plane depicted by angle D in FIG. 6 or the projected angle E of line 46 in the M-L plane as shown in FIG. 6. Thus, projected angles D and E are instead approximately 29° and 8°, respectively. It should also be appreciated that these angle measurements which are typically used as references by those of ordinary skill in the art are only rough approximations as the hand is curved, and that in the present invention the surfaces are actually curved as well to conform to the configuration of the hand of the user.

Also depicted in FIG. 1 is the projection of axis 50 of the metacarpals in the M-L plane. As shown, metacarpal axis 50 forms an angle F of approximately 10° with forearm axis 44.

Extending from volar shell portion 26 is a palm arch support 52. Palm arch support 52 extends adjacent metacarpal hood portion 40 in order to maintain the hand of the user in dorsal hood 38. As shown best in FIGS. 2 and 5, palm arch support 52 includes a cup shape 54 which is designed to rest against the palm of the user. Located between palm arch support 52 and dorsal hood 38 is a thumb opening 56 for the thumb of the user. In order to keep the hand of the user in position between dorsal hood 38 and palm arch support 52, a velcro strap 58 is used which is similar to velcro straps 30. Velcro strap 58 is attached at hook portion 60 to phalanx hood portion 42 by a rivet 62. Suitably attached to sleeve 12 is a ring 64 through which velcro strap 58 is looped in order to bring dorsal hood 38 and palm arch support 52 together and then to hold them in a fixed relationship.

In use, hand splint 10 functions in the following manner. Initially, straps 30 and 58 are withdrawn or substantially loosened from respective rings 36 and 64. Thus, because sleeve 12 is made from a semi-rigid material, dorsal shell portion 24 can be pulled apart from volar shell portion 26 in order to allow the insertion of a patient's hand, wrist, and distal forearm in sleeve 12. Thereafter, straps 30 are fed through respective rings 36 if needed and tensioned in order to provide some soft tissue compression in the distal forearm to aid in maintaining suspension and comfort. After proper tensioning, fibrous portion 32 of each strap 30 is attached to a respective hook portion 34 to maintain a tension in strap 30. In addition strap 58 is fed through ring 64 in order to maintain the hand of the user in position against palm arch support 52, metacarpal hood portion 40, and phalanx hood portion 42. Strap 58 is then attached to hook portion 60 to hold the hand in place.

Once hand splint 10 is attached to the hand, wrist, and distal forearm of the user, it should be appreciated that the thumb of the user extends through thumb opening 56 and provides clearance for the basar joint of the thumb so that the thumb is completely free to move at all joints. In addition, phalanx hood portion 42 covers the proximal phalanges without limiting motion of PIP and DIP joints of the fingers. It should be appreciated that hand splint 10 also initially holds the wrist in a comfortable but maximum angle of dorsiflexion of the wrist of about (or slightly less than) 75° while at the same time maintaining a maximum, comfortable dorsiflexion of slightly less than 90° of flexion of the metacarpal-phalangeal joints. After hand splint 10 is worn for a long period of time, some play will develop and the dorsiflexion angle of the wrist will be reduced. However, this angle should not be less than about 45°, and hand splint 10 is designed to maintain this minimum wrist dorsiflexion by the selection of dorsiflexion angle A between 60° to 80°. Forearm axis 44 also forms approximately a 10° angle of radial deviation to the projection of the axis of the metacarpals in the M-L plane.

Depicted in FIGS. 7-9 is an alternative embodiment of an adjustable hand split 10' which is similar in many respects to hand splint 10. However, as described subsequently, adjustable hand splint 10' includes two adjustments whereby adjustable hand splint 10' can be readily adapted for use with users having different sized hands and arms so that a more universal hand splint is provided. However, the various desired angles of hand splint 10 for maintaining the hand of the user in the described orientations are similarly incorporated in hand splint 10' as well.

For convenience, where hand splint 10' includes substantially the same element as hand splint 10, the same identification numeral will be used with a "'" thereafter. Thus, it will be appreciated that hand splint 10' includes a sleeve 12' which in this embodiment is comprised of four basic parts. Two such parts of sleeve 12 form an elongate shell 20' which extends over the wrist and distal forearm of the user. These two parts are a dorsal shell portion 24' and a volar shell portion 26'. As shown, both dorsal shell portion 24' and volar shell portion 26' are approximately C-shaped with dorsal shell portion 24' being partially received in volar shell portion 26' to form shell 20' completely surrounding the arm of the user. Attached to dorsal shell portion 24' by use of rivets 28' are two velcro straps 30'. In this embodiment, also attached by rivets 28' are rings 36' extending in the opposite direction from straps 30'. It will be appreciated that straps 30' must be long enough to extend completely around shell 20', be looped through respective rings 36', and go back around shell 20' so that the fibrous portions 32' connect with associated hook portions 34' adjacent rivets 28'. As depicted in FIG. 7, straps 30' are simply drawn in the air above shell 20' for clarity.

In adjustable hand splint 10', only dorsal shell portion 24' is provided with an outer material 14' as well as an inner material 16' together with perforations 18'. Volar shell portion 26' is thus simply formed from a molded polyethylene or the like.

Another part of sleeve 12' is a dorsal hood 38' which extends adjustably from dorsal shell portion 24'. Dorsal hood 38' includes a metacarpal hood portion 40' and a phalanx hood portion 42'. Provided in metacarpal hood portion 40' are a pair of parallel slots 70 which are approximately parallel with the hand axis. Extending though respective slots 70 are stems 72 of respective pull rivets 74. As shown in FIG. 10, each pull rivet 74 also includes a head 76 and a resilient locking member 78. Locking member 78 includes a central aperture in which a cylindrical pawl 80 is adapted to slide over and lock upon associated cylindrical ratchets 82 provided on stem 72. Thus, it will be appreciated that dorsal hood 38' is adjustably attached to dorsal shell portion 24' by simply moving locking member 78 onto the first ratchet 82 on stem 72 as shown in the figure while head 76 is held in place by being located on the underneath of dorsal shell portion 24'. After adjustment on the user, a modified pull rivet tool is then simply used to push locking member 78 onto a lower ratchet 82 in order to securely lock dorsal hood 38' in position on dorsal shell portion 24'.

Adjustably attached to volar shell portion 26' and extending therefrom is a palm arch support 52'. The distal end of palm arch support 52' extends adjacent dorsal hood 38' in order to maintain the hand of the user in dorsal hood 38'. Palm arch support 52' includes a cup shape which shape is reinforced by a rib 84.

As shown best in FIG. 9, palm arch support 52' includes an extended portion 86 which lies matingly against the underlying part of volar shell portion 26'. Extended portion 86 includes two elongated slots 88 which are provided with a suitable adjusting and locking means in the form of pull rivets 74 similar to those provided with dorsal hood 38'. Thus, in a similar manner, the position of palm arch support 52' can be adjusted along the forearm axis to properly position the hand of the user between dorsal hood 38' and palm arch support 52'. When in position, pull rivets 74 in slots 88 are similarly locked in place as discussed above.

Attached to phalanx hood portion 42' is a velcro strap 58'. Velcro strap 58' is used to maintain the hand of the user between dorsal hood 38' and palm arch support 52'. Velcro strap 58' is attached to phalanx hood portion 42' by a rivet 62'. On the side of volar shell portion 26' opposite from the side on which rivet 62' is located, a ring 64' is provided through which velcro strap 58' passes before doubling up upon itself and attaching itself to hook portion 60'. When this is accomplished, it should also be appreciated that a thumb opening 56' is provided between palm arch support 52' and dorsal hood 38'.

After pull rivets 74 in metacarpal hood portion 40' and in extended portion 86 of palm arch support 52' are locked in position, that portion of stem 72 extending above locking member 78 is cut off and sanded smooth. In the case of pull rivets 74 extending through slots 88, it should be appreciated that slots 88 are positioned so that respective velcro straps 30' pass over locking members 78 after being looped through respective rings 36'. Thus, any sharp edges or burrs of stem 72 or locking member 78 are covered and the user is protected. In addition, it should be appreciated that volar shell portion 26' is provided with a pair of parallel slots 90 on either side of respective slots 88. Thus, as shown in FIG. 9, each velcro strap 30' is initially threaded underneath extended portion 86 through slots 90 and then out from under extended portion 86. With this configuration, velcro straps 30' also cover the associated heads 76 of pull rivets 74, protecting the arm of the user from rubbing against head 76.

In use, hand splint 10' functions in substantially the same manner as hand splint 10 described above. However, it should be appreciated that rather than prying sleeve 12 apart as with hand splint 10, dorsal shell portions 24' and volar shell portions 26' are simply separated from one another a sufficient distance to allow the user to insert his arm and hand therebetween. At this time, it should be appreciated that velcro straps 30' should be threaded through slots 90 so that velcro straps 30' help to maintain volar shell portion 26' adjacent dorsal shell portion 24' while the separation between these parts is easily adjusted. As discussed above, when the arm and hand of the user are inserted in sleeve 12', both dorsal hood 38' and palm arch support 52' are appropriately positioned and locked into place using locking members 78 of pull rivets 74. Velcro straps 30' and 58' are then threaded through the respective rings 36' and 64' and doubled back upon themselves to securely lock the arm and hand of the user in place in hand splint 10'.

With use of hand splint 10 or 10', it is possible for the user to temporarily remove hand splint 10 or 10' if desired. Furthermore, adjustments for comfort and reduced swelling are further possible as necessary or desired.

It is anticipated that hand splint 10 or 10' of the present invention will have widespread application. In addition to the treatment of wrist fractures, it is also anticipated that the hand splint of the present invention can be used to treat metacarpal fractures and certain fractures of the proximal phalanx which can be reduced by the maneuver of the metacarpal-phalanx joint flexion. It should also be appreciated that dorsal hood 38 aids in the correction dorsal edema of the hand and fingers. While hand splint 10 or 10' does not have specific uses in the management of flexor tendon injuries, by wrist flexion instead of wrist extension, it can be used to manage flexor tendon injuries.

While the present invention has been described with respect to an exemplary embodiment thereof, it will be understood by those of ordinary skill in the art that various changes and modifications can be effected within the scope and spirit of the invention. 

We claim:
 1. A hand splint for immobilizing a hand, wrist, and distal forearm of a user, comprising:a sleeve in which the hand, wrist and distal forearm are received, said sleeve being made of a semi-rigid material and including(a) an elongate shell adapted to extend over the wrist and distal forearm, said shell including a volar shell portion and a dorsal shell portion which is partially received in said volar shell portion; (b) a dorsal hood extending from said dorsal shell portion, said dorsal hood including a metacarpal hood portion which is adapted to cover the dorsum of the hand and a phalanx hood portion which is adapted to cover the proximal phalanges and which terminates thereat; said metacarpal hood portion adapted to form a dorsiflexion angle of between 60° to 80° with the axis of the forearm so that a comfortable maximal dorsiflexion of the wrist is achieved; and said metacarpal hood portion forming a hood angle of between 75° to 90° with said phalanx hood portion; (c) a first attaching and locking means for adjustably attaching said dorsal hood to said dorsal shell portion while said hand splint is being fitted to the user and for subsequently locking said dorsal hood in the adjusted position to said dorsal shell portion after fitting; (d) a palm arch support extending from said volar shell portion, said palm arch support extending adjacent said metacarpal hood portion in order to maintain the hand in said dorsal hood with the wrist in dorsiflexion by abutment with said metacarpal hood portion and the metacarpal-phalangeal joints at an angle of greater than about 90° to 105° by abutment of the proximal phalanges with said phalanx hood portion; (e) a second attaching and locking means for adjustably attaching said palm arch support to said volar shell portion while said hand splint is being fitted to the user and for subsequently locking said palm arch support in the adjusted position to said volar shell portion after fitting; and (f) a thumb opening between said dorsal hood and said palm arch support defined by borders thereof, said borders being adapted to be recessed from the thumb such that the thumb of the user extends through the thumb opening and all joints of the thumb are free to move; and a holding means for holding said sleeve in radial abutment with the hand, wrist and distal forearm of the user.
 2. A hand splint as claimed in claim 1 wherein the hood angle is slightly less than 90°.
 3. A hand splint as claimed in claim 2 wherein the dorsiflexion angle is about 75°.
 4. A hand splint as claimed in claim 3 wherein a line formed by the apexes of the hood angle is adapted to form an angle of about 60° with respect to the longitudinal axis of the hand projected on the metacarpal hood portion.
 5. A hand splint as claimed in claim 1 wherein a line formed by the apexes of the hood angle projected onto the M-L plane forms an angle of about 80° with the forearm axis.
 6. A hand splint as claimed in claim 1 wherein said holding means is at least two straps and associated securing means for securing said straps in tension between said volar shell portion and said dorsal shell portion to radially compress the distal forearm, and a strap and associated securing means for securing said last-mentioned strap in tension between said volar shell portion and said dorsal hood to maintain the hand in said dorsal hood.
 7. A hand splint as claimed in claim 1 wherein said sleeve is covered on an inside portion thereof with a resilient material, and a plurality of apertures are provided through said sleeve and said resilient material.
 8. A hand splint as claimed in claim 1 wherein said first attaching and locking means includes a pair of first slots in said metacarpal hood portion approximately parallel with the hand axis and a pair of first pull rivets, each said first pull rivet disposed through a respective said first slot.
 9. A hand splint as claimed in claim 8 wherein said second attaching and locking means includes a pair of second slots in said palm arch support approximately parallel to the forearm axis and a pair of second pull rivets, each said pull rivet disposed through a respective said second slot.
 10. A hand splint for immobilizing a hand, wrist, and distal forearm of a user, comprising:a sleeve in which the hand, wrist and distal forearm are received, said sleeve being made of a semi-rigid material and including(a) an elongate shell adapted to extend over the wrist and distal forearm, said shell including a volar shell portion and a dorsal shell portion which is partially received in said volar shell portion; (b) a dorsal hood extending from said dorsal shell portion, said dorsal hood (i) including a metacarpal hood portion which is adapted to cover the dorsum of the hand and a phalanx hood portion which is adapted to cover the proximal phalanges and which terminates thereat, (ii) being adapted to form a dorsiflexion angle of about 75° with the axis of the forearm so that a comfortable maximal dorsiflexion of the wrist is achieved, (iii) forming a hood angle of slightly less than 90° with said phalanx hood portion, and (iv) being adapted to have the apexes of said hood angle forming an angle of about 60° with respect to the longitudinal axis of the hand projected on said metacarpal hood portion; (c) a first attaching and locking means for adjustably attaching said dorsal hood to said dorsal shell portion while said hand splint is being fitted to the user and for subsequently locking said dorsal hood in the adjusted position to said dorsal shell portion after fitting; (d) a palm arch support extending from said volar shell portion, said palm arch support extending adjacent said metacarpal hood portion in order to maintain the hand in said dorsal hood with the wrist in dorsiflexion by abutment with said metacarpal hood portion and the metacarpal-phalangeal joints at an angle of greater than about 90° by abutment of the proximal phalanges with said phalanx hood portion; and (e) a second attaching and locking means for adjustably attaching said palm arch support to said volar shell portion while said hand splint is being fitted to the user and for subsequently locking said palm arch support in the adjusted position to said volar shell portion after fitting; and (f) a thumb opening between said dorsal hood and said palm arch support defined by borders thereof, said borders being adapted to be recessed from the thumb such that the thumb of the user extends from the thumb opening and all joints of the thumb are free to move; and a holding means for holding said sleeve in radial abutment with the hand, wrist and distal forearm of the user.
 11. A hand splint for immobilizing a hand, wrist, and distal forearm of a user, comprising:a sleeve in which the hand, wrist and distal forearm are received, said sleeve being made of a semi-rigid material and including(a) an elongate shell adapted to extend over the wrist and distal forearm, said shell including a volar shell portion and a dorsal shell portion; (b) a dorsal hood extending from said dorsal shell portion, said dorsal hood including a metacarpal hood portion which is adapted to cover the dorsum of the hand and a phalanx hood portion which is adapted to cover the proximal phalanges and which terminates thereat; said metacarpal hood portion adapted to form a dorsiflexion angle of between 60° to 80° with the axis of the forearm so that a comfortable maximal dorsiflexion of the wrist is achieved; (c) a first attaching and locking means for adjustably attaching said dorsal hood to said dorsal shell portion while said hand splint is being fitted to the user and for subsequently locking said dorsal hood in the adjusted position to said dorsal shell portion after fitting; (d) a palm arch support extending from said volar shell portion, said palm arch support extending adjacent said metacarpal hood portion in order to maintain the hand in said dorsal hood with the wrist in dorsiflexion by abutment with said metacarpal hood portion; (e) a second attaching and locking means for adjustably attaching said palm arch support to said volar shell portion while said hand splint is being fitted to the user and for subsequently locking said palm arch support in the adjusted position to said volar shell portion after fitting; and (f) a thumb opening between said dorsal hood and said palm arch support defined by borders thereof, said borders being adapted to be recessed from the thumb such that the thumb of the user extends through the thumb opening and all joints of the thumb are free to move; and a holding means for holding said sleeve in radial abutment with the hand, wrist and distal forearm of the user. 